Extremely Low Program Current Memory Based on Self-Assembled All-Inorganic Perovskite Single Crystals

Memory devices based on lead halide perovskite have attracted great interests because of their unique current-voltage hysteresis. However, current memory devices based on polycrystalline perovskites usually suffer from large intrinsic electronic current and parasitic leakage current due to the existence of grain boundaries, which further leads to high power consumption. Here, a low-power resistance switching random-access memory device is demonstrated by assembling single-crystalline CsPbBr₃ on Ag electrodes. The assembled structure serves as a bipolar nonvolatile resistance switching memory device with a low program current (∼10 nA), good endurance, long data retention (>10³ S), and big on/off ratio of ∼10³. The low program current results in a power of ∼3 × 10^-8 W, which is much lower than that of polycrystalline perovskite-based devices (10^-1-10^-6 W). It is found that the formation and annihilation of Ag and bromide vacancy conductive filaments contribute to the significant resistive switching effect. At a low resistive state, the conductive filaments originate from the accumulation of Br^- ions at the drain. Furthermore, the conductive filaments are proved to be a cone shape, shrinking from the drain to the source.